illustrator_set_reference

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructive=true, readOnly=false, idempotent=true, and openWorld=true, and the description adds substantial behavioral detail: layer is locked/dimmed/non-printable, repeated calls replace the previous reference, clear deletes the layer, active artboard is used for fit, and dominant colors are extracted when Pillow is available. This goes well beyond the structured annotations and matches them with no contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is long but every section earns its place: contract, usage triggers, key behavioral concepts, examples, and migration notes. It is front-loaded with the core purpose and uses structured headings and concrete example payloads, making it easy for an agent to scan and act on.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutate tool with no output schema, the description covers what the operation does, what it affects (dedicated layer), how idempotency works, legacy behaviors, required vs omitted parameters, and even edge cases like empty calls rejecting. An agent has enough context to invoke set or clear correctly without additional inference.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries the burden of explaining parameters. It does so thoroughly: action set/clear, file_path required for set, opacity default of 40 for dimming, fit behavior, legacy nonempty file_path meaning set, and the need to omit file_path/opacity/fit on clear. This compensates fully for the schema gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Set or clear a reference image on a locked background layer for tracing.' It clearly distinguishes this from ordinary file placement by mentioning the dedicated '__reference__' layer, locked/dimmed/non-printable, and tracing purpose. The action parameter (set vs clear) is unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The 'WHEN TO USE' section explicitly names the two scenarios: preparing a tracing reference and clearing a previous reference. It does not explicitly compare with sibling tools like illustrator_place_file, but the tracing-specific context strongly implies the appropriate selection, so this is clear guidance with only a minor missing exclusion.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.